1. Field of the Invention
The invention relates to a biased support for booms that can pivot about a pin, for pivoting travel tracks for vehicles that run on rails, such as trolley travel tracks on booms. The invention can be used anywhere where travel tracks of vehicles that run on rails, particularly crane trolleys, which run on a divided (joined) travel track during their operation and must pass over this travel track join, are present.
2. The Prior Art
Such travel tracks can be disposed on cranes, for example portal cranes such as container cranes, bridge cranes, or the like. These cranes have the bridge part with a horizontal travel track for the trolley on the crane, and a foldable travel beam that is disposed to rotate in a bearing, about an axis. A boom lock that absorbs forces between travel beam and crane connects the bridge part with the boom. Slide plates with which the travel beam moves into the crane part are disposed on the boom lock.
Such a bearing is described, for example, in German Patent No. DE 102 39 565 A1, whereby the travel tracks over the boom lock was not described.
Typically, the movable part of the travel tracks, which can be situated on a folding boom, are vertically supported in their operating position, i.e., in a horizontal position, by means of a type of support. The vertical forces from the weight of the boom itself and of the vehicle that runs on it, for example a crane trolley, is transferred from the fixed part to the movable part of the travel track not by way of the pin of the boom joint, but rather by way of the rigidly mounted slide plates. For this purpose, the boom lock described above was created for the operating position of the boom, which lock consists of an upper bearing point having an upper and lower slide plate, and a lower bearing point having an upper and lower slide plate. In connection with the construction and function of such a lock-like connection, the slide plates and their infrastructure are usually mounted in an approximately stress-free manner, since the weight force of the boom during pivoting into the horizontal position and accordingly also in the horizontal position are not transferred exclusively by way of the joint pin.
If the connection between the fixed and movable parts of the travel track is now stressed by a changeable load, for example a traveling crane trolley, the joint pin will deform, along with its bearing, and the entire infrastructure up to the travel track, before pressure stress is placed on the slide plates. This deformation of the component lying in the force flow results in a vertical displacement of the two rail ends, resulting in premature wear and poor operating behavior.